Bob Dole, the former Senate Republican leader, wrote an insistent letter to Rush Limbaugh on Monday and suggested that for the good of the party, the conservative talk-show host should stop his strafing of Sen. John McCain (R-Ariz.).

On Monday's show, Limbaugh asserted that McCain has "lied about his reason for opposing the Bush tax cuts," and added: "I think McCain has an animus toward the Republican Party. I think ever since South Carolina 2000 he's had it in for the Republican Party, and one of his objectives is to destroy it and change it."

McCain, the front-runner for the Republican presidential nomination, has always had a shaky relationship with the party’s conservative base.

In a letter released Monday evening by McCain's campaign, Dole strongly defended the senator’s conservative credentials, noting that his voting record is opposed to abortion and supportive of gun-owner rights.

As McCain’s campaign gained steam, Limbaugh has used the airwaves to remind listeners daily that he does not consider the senator to be a conservative.

Limbaugh has even suggested he might not vote Republican if McCain were the nominee.

A day ahead of the potentially decisive Super Tuesday primaries, Limbaugh launched new attacks on the senator during Monday’s broadcast, declaring: “John McCain has stabbed his own party in the back, I can’t tell you how many times.”

Dole wrote that as the former Senate Republican leader, he could vouch for the fact that McCain supported the party on all “critical votes.”

In a bill of particulars numbered 1 through 8, Dole wrote that McCain has a “Consistent pro-life record,” was a “Strong advocate for strict constructionist judges,” “Supported voluntary school prayer,” supported a balanced-budget amendment, was a strong advocate for cutting spending, consistently defended Second Amendment (gun-owner) rights, “opposed ‘Hillary Care,’ ” and was “Probably the Senate's strongest advocate for strong national defense.”

The letter begins simply “Rush.”

“I have not seen you in a long time but I do hear you frequently and I know that you have serious reservations about Senator McCain,” Dole wrote.

“McCain is a friend and I proudly wore his P.O.W. bracelet bearing his name while he was still a guest at the ‘Hanoi Hilton.’ I believe our major candidates are mainstream conservatives and that our nominee will address our concerns by keeping taxes low, reducing corporate taxes, protecting and assisting the vulnerable, strengthening our traditional values, and above all, keeping America strong militarily, whatever the cost.

As a P.S., Dole adds a table from the Senate Library showing that McCain’s voting record — as measured by support for the president — mirrored that of the ultra- conservative former U.S. Sen. Jesse Helms (R-N.C.).

On Monday’s broadcast, Limbaugh said in an audio clip posted at “The Page” on TIME.com: “He stabbed his own president in the back on legislation, a number of times. He doesn’t support his party or his president when the chips are down. He called people who want to protect the border racists, nativists, protectionists, and worse. And what kind of character is it that tries to slide all that through under cover of darkness, in a back room.”

During a broadcast last week that is transcribed on Limbaugh’s Web site, he said McCain enjoys the affection of the left and the media: “I think one of the reasons they're able to embrace candidates like Senator McCain is that he's been so willing to cast conservative principles aside when it makes sense for him politically, socially, or what have you.”